Microparticles or nanoparticles are often referred to as structures whose characteristic dimensions are on the order of micrometers or less, such as those with volumes of 1 mm3 or less. Due to their unique properties arising from their small characteristic dimensions, microparticles have found distinguishable applications in laboratory research and many industrial fields. Encoded microparticles possess a means of identification and are an important subclass of the general field of microparticles. Because encoded particles carry information and can be physically tracked in space and time, they greatly extend the capabilities of non-encoded particles. A particularly important application for encoded microparticles is multiplexed bioassays, including those involving DNA and proteins. Other important fields for encoded microparticles include combinatorial chemistry, tagging, etc. Many biochemical and non-biochemical applications as will be discussed herein below.
For many applications, one more desirable attributes include: a large number of identifiable codes (i.e. a high codespace), accurate and reliable identification of the encoded particles, material compatibility for a particular application, low cost manufacturing of the microparticles (on a per batch, per particle, and per code set basis), and flexibility in the detection systems.
Several approaches to produce encoded microparticles have been developed in the past, such as fragmented colored laminates, colored polystyrene beads, quantum dot loaded polymer beads, rare-earth doped glass microbarcodes, electroplated metal nano rods, diffraction grating based fiber particles, and pattern bars and disks, and other types of microparticles. These technologies however suffer from any of a number of limitations, such as, insufficient codespace, high cost, inadequate precision, poor performance in applications, problematic clumping incapability of large scale manufacture, and complicated preprocessing or assay procedures.
Therefore, what is desired is an encoded microparticle or a set of encoded microparticles carrying coded information, methods of making the same, methods for providing the codes for microparticles, methods for fabricating the microparticles, methods and systems for detecting microparticle, and methods and systems for using.